Bombus hypnorum, the tree bumblebee or new garden bumblebee, is a species of bumblebee that is common on the European continent and parts of Asia. It has recently spread to United Kingdom and Iceland.
(From Wikipedia)

Bombus terrestris, the buff-tailed bumblebee or large earth bumblebee is one of the most numerous bumblebee species in Europe. The queen is 2–2.7 cm long, while the workers are 1½–2 cm. The latter are characterized by their white-ended abdomens and look (apart from their yellowish bands being darker in direct comparison) just like those of the white-tailed bumblebee, B. lucorum, a close relative. The queens of B. terrestris have the namesake buff-white abdomen ("tail") tip; this area is...
(From Wikipedia)

Bombus hortorum is a species of bumblebee. It bears the common name garden bumblebee or small garden bumblebee, and can be found in most of Europe up to 70ºN, as well as parts of Asia and New Zealand.
(From Wikipedia)